I went through something similar when I first set up my rooftop garden. Initially, I thought heavier soil would hold moisture better, but it just compacted and drained poorly. Switched to a lighter, aerated mix with perlite and coconut coir, and the difference was night and day. Plants perked right up, and maintenance became way simpler. Definitely worth experimenting a bit to find what clicks for your setup...
"Initially, I thought heavier soil would hold moisture better, but it just compacted and drained poorly."
Yeah, heavier mixes can be tricky—especially if your rooftop gets a lot of rain or wind. Lighter mixes drain better, but watch out they don't dry out too fast in hot weather... balancing act for sure.
Definitely agree—heavier soils often cause more issues than they're worth, especially on rooftops where structural load and drainage are critical. You might consider a lighter mix with perlite or pumice to enhance drainage without sacrificing moisture retention. Also, adding organic matter like compost can help balance moisture levels. Just keep an eye out for settling over time... rooftop gardens can shift more than you'd expect, so periodic adjustments might be needed.
